| 摘要 |
PURPOSE:To reduce the overshoots of a motor current and a torque by setting a slip frequency to zero at the time of switching the output of an inverter from a modulation range to a nonmodulation range. CONSTITUTION:When a power drive renotch or electric brake is operated in a high speed range of an electric railcar, the output voltage V of an inverter 5 is switched from a modulation range to a nonmodulation range. In this case, a slip frequency fs is set to zero or the prescribed range, the voltage V is risen to the nonmodulation range, and the frequency fs is then controlled to obtain a necessary torque. Thus, the overshoots of a torque shock and a motor current can be prevented at the time of switching from the modulation range to the nonmodulation range. |
